<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    
    <script>
        function Demo(){
            this.a = 1
            this.b = 2;
        }
        const d = new Demo();
        console.log(Demo.prototype)
        console.log(d.__proto__)
        console.log(Demo.prototype == d.__proto__)
    </script>
</body>
</html>